The research study will try to answer the question whether in vivo generation of volatile nitrosmaines occur in the gut of patients with chronic renal failure. This is proposed because of the finding that bacterial overgrowth and high levels of secondary amines occur in the proximal small intestine in patients with advanced kidney failure. A high incidence of cancer in end-stage kidney disease has been reported from various parts of the world including the United States. We are currently examining biological fluids in patients with end-stage kidney disease for precursor compounds and nitrosamines. These measurements for nitrosamines are being performed by gas chromatography thermal energy analysis. Also, and epidemiological survey is being carried out to define more carefully the true incidence of cancer in chronic renal failure. Preliminary results show that nitrosamine generation is occuring in water treatment systems used for dialysing patients with chronic renal failure. Because of the potential danger of this finding, exact definition of this occurrence is being intensively studied. A source for ex vivo nitrosamine formation has been identified in dialysis units, and measured in the blood of patients where such nitrosamine production has occurred. The implications of this work are obvious in reviewing water treatment systems.